Open surgery is still the standard technique for most surgical procedures. It has been used by the medical community for several decades and consists of performing the surgical tasks through a long incision in the abdomen, through which traditional surgical tools are inserted. However, due to the long incision, this approach is extremely invasive for the patients, resulting in substantial blood loss during the surgery and long and painful recovery periods at the hospital.
In order to reduce the invasiveness of open surgery, laparoscopy, a minimally invasive technique, was developed. Instead of a single long incision, four to five small incisions are made in the patient through which appropriately sized surgical instruments and endoscopic cameras are inserted. Because of the low invasiveness, this technique reduces blood loss and shortens hospital stays and pain. When performed by experienced surgeons, this technique can attain clinical outcomes similar to open surgery. However, despite the above-mentioned advantages, laparoscopy requires extremely advanced surgical skills to manipulate the rigid and long instrumentation. The entry incision acts as a point of rotation, decreasing the surgeon's freedom for positioning and orientating the instruments inside the patient. The movements of the surgeon's hand about this incision are inverted and scaled-up relative to the instrument tip (“fulcrum effect”), which removes dexterity, sensibility and magnifies the tremors of the surgeon's hands. In addition, these long and straight instruments force surgeons to work in a uncomfortable posture, which can be tremendously tiring during several hours of operation and result in stress and discomfort for hands, arms and body. Therefore, due to these drawbacks of laparoscopic instrumentation, these minimally invasive techniques are mainly limited to use in simple surgeries, while only a small minority of surgeons is able to use them in complex procedures.
To overcome these limitations, surgical robotic systems were developed to provide an easier-to-use approach to complex minimally invasive surgeries. By means of a computerized robotic interface, these systems enable the performance of remote laparoscopy wherein the surgeon sits at a console manipulating two master manipulators to perform the operation through several small incisions. Like laparoscopy, the robotic approach is also minimally invasive, bringing several advantages over open surgery in terms of reduced pain, blood loss, and recovery time. In addition, it also offers better ergonomy for the surgeon compared to open and laparoscopic techniques. However, although being technically easier, robotic surgery brings several negative aspects. A major disadvantage of these systems is related to the extremely high complexity of existing robotic devices, which are composed of complex mechanical and electronic systems, leading to huge costs of acquisition and maintenance, which are not affordable for the majority of surgical departments worldwide. Another drawback of these systems comes from the fact that current surgical robots are very large, competing for precious space within the operating room environment and significantly increasing preparation time. Access to the patient is thus impaired, which, together with a lack of force-feedback, raises safety concerns.
WO9743942, WO9825666 and US2010011900 disclose a robotic tele-operated surgical instrument, designed to replicate a surgeon's hand movements inside the patient's body. By means of a computerized, robotic interface, it enables the performance of remote laparoscopy wherein the surgeon sits at a console manipulating two joysticks to perform the operation through several small incisions. However, this system does not have autonomy or artificial intelligence, being essentially a sophisticated tool fully controlled by the surgeon. The control commands are transmitted between the robotic master and robotic slave by a complex computer-controlled mechatronic system, which is extremely costly to produce and maintain and difficult to use for the hospital staff.
WO2013014621 describes a mechanical telemanipulator for remote manipulation with a master-slave configuration, comprising a slave manipulator driven by a kinematically equivalent master manipulator and a mechanical transmission system such that each part of the slave manipulator mirrors the movement of each corresponding part of the master manipulator. Therefore, this system allows surgeons to perform surgical procedures by directly manipulating a control handle in the proximal part of the mechanical telemanipulator while their movements are replicated (scaled down or not) by an articulated instrument that can reach the abdominal cavity of the patient through small incisions or trocars. Although the mechanical transmission system is well adapted to the device, the kinematic model and transmission topology of the handle were not optimized, forcing surgeons to move their hands in non-ergonomic ranges of motion and limiting the amount of gripping force that can be generated at the instrument's end-effector.
Accordingly, an aim of the present invention is to provide a mechanical telemanipulator handle mechanism with a new configuration, which is able to deliver higher gripping forces to the instrument's end-effector.
Another aim of the present invention is to provide a mechanical telemanipulator handle mechanism with a more ergonomic range of motion for the surgeon's hands.